Duração da gestação e do parto em éguas Puro Sangue Árabe

Factors affecting gestational length in the Mangalarga Paulista breed

“…These results differ from the majority of data for different breeds, in which the gestation length for colts was longer than that for fillies (Bos and Van Der Mey, 1980;Davies Morel et al, 2002;Pérez et al, 2003;Valera et al, 2006;Satué et al, 2011a b;Aoki et al, 2012;McCue and Ferris, 2012). Only few publications were not able to detect a significant influence of gender on the length of gestation (Campitelli et al, 1982;Valente et al, 2006), as it was found in our study. As a tendency of longer gestation for colts (P = 0.074) was found, probably an increase in the number of observations could have been able to find an effect of gender.…”

“…Regarding the effect of parity, primiparous mares had longer gestation than multiparous mares, with a mean of 347.76 ± 1.90 days for primiparous mares (Table 2), and these results corroborate those found by Pool-Anderson et al (1994), Valente et al (2006), Satué et al (2011b) and Kuhl et al (2015). According to Valera et al (2006), the gestation length decreases until the fourth and fifth parity, then increases progressively in subsequent births.…”

Gestation length variation in domesticated horses and its relation to breed and body size diversity

“…Our dataset included five breeds for which we also found values of mean gestation length in the literature (Table 1). In Arabs, our dataset resulted in a mean gestation length of 342 days and literature results range from 330.42 (Valente et al, 2006) to 340.3 (Valera et al, 2006) days. For Freiberger (341.9 days) only one comparing study could be found with an average gestation length of 336.5 days (Giger et al, 1996).…”

“…This is hypothesized to be caused by testosterone or chromosome linked effects (Cilek, 2009), differences in the interaction with endocrine control of parturition (Jainudeen and Hafez, 2000), or a more developed allontochorion in colts (Wilsher and Allen, 2003). In contrast to the high number of publications on this subject, two studies could not find differences between male and female foals (El-Wishy et al, 1990;Valente et al, 2006).…”

“…Several studies discuss the influence of additional factors such as climate (Mauch, 1937), stud farm where the mares are located during the gestation period (Aoki et al, 2013;Davies Morel et al, 2002;Langlois and Blouin, 2012;Van Rijssen et al, 2010), feeding management (Thorson et al, 2010;Uppenborn, 1933), type of insemination (Bene et al, 2014), inbreeding (Langlois and Blouin, 2012), length of last gestation period (Aoki et al, 2013), interval from ovulation to mating (Davies Morel et al, 2002), unspecified characteristics of the individual mare (Giger et al, 1996;Uppenborn, 1933;Valera et al, 2006;Van Rijssen et al, 2010), reproductive status of the mare (Van Rijssen et al, 2010), parity of the mare (Aoki et al, 2013;El-Wishy et al, 1990;Pool-Anderson et al, 1994;Sanchez, 1998;Staffe, 1935;Valente et al, 2006;Valera et al, 2006;Winter et al, 2007), age of the mare (Aoki et al, 2013;Bene et al, 2014;Bos and Van der Mey, 1980;Cilek, 2009;Davies Morel et al, 2002;Demirci, 1988;Guay et al, 2002;Heidler et al, 2004;Hintz et al, 1992;Kurtz Filho et al, 1997;Langlois and Blouin, 2012;Mauch, 1937;Sevinga et al, 2004;Valera et al, 2006;…”